Dear Doctor: A colleague just returned from a long hospital stay, where he battled a C. diff infection. He had asked for a fecal transplant but was refused. Will these ever become the standard of care? Are there uses for these procedures other than to fight C. diff infections?
Dear Reader: For those of you who may not be familiar with the topic, a fecal transplant is the introduction of stool from a healthy donor into the gastrointestinal tract of a recipient. You may also hear this referred to as a fecal microbiota transplant, or FMT. The goal is to repopulate the colon of the recipient with friendly bacteria that have been killed or depleted, often as a result of antibiotics.
The procedure has been most widely used in treating Clostridium difficile, or C. diff, a stubborn bacterium that can overpopulate the colon when one's own intestinal flora are wiped out. Symptoms range from ongoing diarrhea to colitis, an inflammation of the colon that can be life-threatening. The stool for a fecal transplant comes from donors who have been screened for a variety of criteria, including parasites and a wide range of pathogens that include E. coli, norovirus, HIV and hepatitis. The stool is then processed into a liquid and introduced into the recipient via an enema, endoscope, colonoscopy or nasogastric tube. As research into the procedure continues, freeze-dried fecal microbiota in capsule form are being developed.
While fecal transplants have entered the public conversation in just the last few years, they date back at least to the 4th century. Writings indicate they were used in China to treat diarrhea and food poisoning. A surge of interest in the practice among European scientists in the 18th century, who were intrigued by its use in other cultures, set the foundation for the modern-day study of microbiota. Following the rise of antibiotics in the 1940s, which cured infectious diseases but decimated the patient's own intestinal flora, scientists continued to experiment with therapeutic uses of FMT.
Today, FMT is used on a case-by-case basis. As your colleague has discovered, not every medical center offers the procedure, and not every patient qualifies for the treatment. According to the most recent FDA enforcement policy, FMT should be used only in C. diff. cases that are not responding to conventional drug therapy. However, considering the pace of research into the gut microbiome, and the enormous interest in the therapeutic potential of FMT, it's likely these guidelines will be continually revisited and amended.
Statistics about the success rate of FMT in treating C. diff infections are hard to pin down. Initial recovery rates are well above 90 percent. But treatment protocols have not yet been standardized. Depending on how donor stool has been processed and administered, relapse rates as high as 50 percent have been observed. Still, the procedure holds great promise. In addition to C. diff infections, it has been successful in treating Crohn's disease and ulcerative colitis. Ongoing research into the treatment of a range of metabolic and autoimmune diseases has yielded surprising results.
We expect that we'll all be hearing and reading about significant advances in the field in the years to come.
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